BBC reports:
In the UK, it was first identified in the middle of October from a sample taken in September.
They made no warning that something had changed. Even on 1st Dec they obviously knew that matters were changing rapidly. Last Wednesday in the House of Commons, Johnson said that Christmas was going ahead - yet he must have known of the developments of the previous 8 weeks and where the numbers were going.
As was pointed out in The Guardian today, Boris postpones making a decision until all of the options have foreclosed with the passage of time. Then he is left with one option and trumpets that as the best option.
The pattern is one of resisting taking the necessary steps at the time when they would have been most effective and then being compelled to implement them late and with more damaging effect.